selectLabelsBySignalType

Select multisignal ground truth labels by signal type

Syntax

gtLabel = selectLabelsBySignalType(gTruth,signalTypes)

Description

gtLabel = selectLabelsBySignalType(gTruth,signalTypes) selects labels of the signal types specified by signalTypes from a groundTruthMultisignal object, gTruth. The function returns a corresponding groundTruthMultisignal object, gtLabel, that contains only the selected labels. If gTruth is a vector of groundTruthMultisignal objects, then the function returns a vector of corresponding groundTruthMultisignal objects that contain only the selected labels.

Examples

Select Ground Truth Labels by Signal Type

Select ground truth labels from a groundTruthMultisignal object by specifying a signal type.

Load a groundTruthMultisignal object containing ROI and scene label data for a video and corresponding lidar point cloud sequence. The helper function used to load this object is attached to the example as a supporting file.

gTruth = helperLoadGTruthVideoLidar;

Inspect the label definitions. The object contains definitions for image, point cloud, and time signals.

gTruth.LabelDefinitions

ans =

  5×7 table

      Name       SignalType    LabelType       Group        Description           LabelColor            Hierarchy  
    _________    __________    _________    ____________    ___________    ________________________    ____________

    {'car'  }    Image         Rectangle    {'Vehicles'}    {0×0 char}     {[0.5862 0.8276 0.3103]}    {1×1 struct}
    {'car'  }    PointCloud    Cuboid       {'Vehicles'}    {0×0 char}     {[0.5862 0.8276 0.3103]}    {1×1 struct}
    {'truck'}    Image         Rectangle    {'Vehicles'}    {0×0 char}     {[     0.5172 0.5172 1]}    {0×0 double}
    {'truck'}    PointCloud    Cuboid       {'Vehicles'}    {0×0 char}     {[     0.5172 0.5172 1]}    {0×0 double}
    {'sunny'}    Time          Scene        {'None'    }    {0×0 char}     {[     0 0.7241 0.6552]}    {0×0 double}

Inspect the ROI labels. The object contains labels for the lidar point cloud sequence and the video.

gTruth.ROILabelData

ans = 

  ROILabelData with properties:

                lidarSequence: [34×2 timetable]
    video_01_city_c2s_fcw_10s: [204×2 timetable]

Create a new groundTruthMultisignal object that contains labels for only point cloud signals.

signalTypes = vision.labeler.loading.SignalType.PointCloud;
gtLabel = selectLabelsBySignalType(gTruth,signalTypes);

For the original and new objects, inspect the first five rows of label data for the lidar point cloud sequence. Because lidar signals are of type PointCloud, the new object contains the same label data for the lidar sequence as the original object.

lidarLabels = gTruth.ROILabelData.lidarSequence;
lidarLabelsSelection = gtLabel.ROILabelData.lidarSequence;

numrows = 5;
head(lidarLabels,numrows)
head(lidarLabelsSelection,numrows)

       Time            car            truck    
    ___________    ____________    ____________

    0 sec          {1×1 struct}    {1×0 struct}
    0.29926 sec    {1×1 struct}    {1×0 struct}
    0.59997 sec    {1×1 struct}    {1×0 struct}
    0.8485 sec     {1×1 struct}    {1×0 struct}
    1.1484 sec     {1×1 struct}    {1×0 struct}

       Time            car            truck    
    ___________    ____________    ____________

    0 sec          {1×1 struct}    {1×0 struct}
    0.29926 sec    {1×1 struct}    {1×0 struct}
    0.59997 sec    {1×1 struct}    {1×0 struct}
    0.8485 sec     {1×1 struct}    {1×0 struct}
    1.1484 sec     {1×1 struct}    {1×0 struct}

For the original and new objects, inspect the first five rows of label data for the video. Because video signals are of type Image, the new object contains no label data for the video.

videoLabels = gTruth.ROILabelData.video_01_city_c2s_fcw_10s;
videoLabelsSelection = gtLabel.ROILabelData.video_01_city_c2s_fcw_10s;

head(videoLabels,numrows)
head(videoLabelsSelection,numrows)

      Time          car            truck    
    ________    ____________    ____________

    0 sec       {1×3 struct}    {1×0 struct}
    0.05 sec    {1×3 struct}    {1×0 struct}
    0.1 sec     {1×3 struct}    {1×0 struct}
    0.15 sec    {1×3 struct}    {1×0 struct}
    0.2 sec     {1×3 struct}    {1×0 struct}

      Time  
    ________

    0 sec
    0.05 sec
    0.1 sec
    0.15 sec
    0.2 sec

Input Arguments

gTruth — Multisignal ground truth data

groundTruthMultisignal object | vector of groundTruthMultisignal objects

Multisignal ground truth data, specified as a groundTruthMultisignal object or vector of groundTruthMultisignal objects.

signalTypes — Signal types

vision.labeler.loading.SignalType enumeration | vector of vision.labeler.loading.SignalType enumerations

Signal types, specified as a vision.labeler.loading.SignalType enumeration or vector of vision.labeler.loading.SignalType enumerations.

To view all signal types in a groundTruthMultisignal object, gTruth, enter this command at the MATLAB^® command prompt.

unique(gTruth.LabelDefinitions.SignalType)

Example: vision.labeler.loading.SignalType.Image

Example: [vision.labeler.loading.SignalType.Image vision.labeler.loading.SignalType.PointCloud]

Output Arguments

gtLabel — Ground truth with only selected labels

groundTruthMultisignal object | vector of groundTruthMultisignal objects

Ground truth with only the selected labels, returned as a groundTruthMultisignal object or vector of groundTruthMultisignal objects.

Each groundTruthMultisignal object in gtLabel corresponds to a groundTruthMultisignal object in the gTruth input. The returned objects contain only the labels that are of the signal types specified by the signalTypes input.

Limitations

• Selecting sublabels by signal type is not supported.

Version History

Introduced in R2020a